A cane filled with water is revolved in a vertical circle of radius 4 m and water just does not fall down. The time period of revolution will be –

Options

A. 2 s
B. 4 s
C. 8 s
D. 10 s

Answer

B

Explanation

Water will not fall if weight is balanced by centripetal force .Therefore, `=(mv^(2))/®`
`rArr " "V^2=rg" "....(i)`
time for a revolution `=(2pir)/(v)`
On putting the value of v from Eq.(i), we get
`T =(2pir)/sqrt(gr)=2pisqrt((r)/(g))=2pisqrt((4)/(9.8))=(4pi)/sqrt9.8=4s`